Similar Species: No similar species occur in the San Mateo Mountains. The most similar allopatric species is Penstemon oliganthus, which is distinguished by obscurely puberulent stems and horizontal or drooping flowers. Penstemon inflatus has a decidedly inflated corolla tube and P. metcalfei has glabrous stems and larger stem leaves and bracts.

Distribution: New Mexico, Socorro County, Magdalena and northern San Mateo mountains.